Midwives and Uterine Rupture: What We Have to Offerby Kristin Eggleston

True uterine rupture is a grave complication of pregnancy and childbirth, one that can lead to death of the baby and/or the mother. Fortunately, the causes of rupture and signs of impending rupture are often blatantly obvious, giving adequate time for treatment, and it has become quite rare. Today, however, ruptures almost exclusively occur in uteri that have been scarred by surgery, most often a previous cesarean, or that have been induced or augmented with synthetic hormones. With a cesarean rate now over 30% in the US (1), almost half of all labors being induced artificially (2) and a potential increase in the number of true uterine ruptures, we need to seriously evaluate the practices of midwives and how they positively affect uterine rupture.

Given that uterine rupture is much more likely in the presence of a scar and/or synthetic hormones, one could reasonably assume that caregivers who have low rates of these interventions also have lower rates of rupture. Studies have shown that midwives have much lower rates of interventions and comparable mortality rates than do hospitals treating similar low-risk women.(3) Of particular importance, the cesarean rate varies from <2% for all births begun on The Farm (4), to 3.7% for all births assisted by certified professional midwives (CPMs) in 2000 (5), and up to 13% for births including vaginal births after cesarean (VBAC) (6), all coming in well below the World Health Organization (WHO) international goal of <15%.(7) (Editors note: In 2009, the WHO updated its stance on cesarean rates, stating that there is no optimum range and recommending that world regions may want to use a range of 515%, or set their own standards.) Also, see article by Gaskin, Ina May, Midwifery Today, Issue 82, discussing The Farm’s policy of prohibiting VBACs for women whose cesarean wounds were sutured with a single layer.)

In the CPM 2000 study, homebirth midwives had rates of 9.6% and 9.2% for induction and stimulation of labor of low-risk, singleton pregnancies, compared to 21% and 18.9% in similarly risked women in the hospital and 44% and 53% for singleton births in all risk categories nationally.

The major factor influencing the positive outcomes for midwives is the focus on the prevention of complications. Midwives are able to accomplish this by various means: 1) sound clinical judgment, which includes close observation and referral as needed; 2) their belief in the normalcy—rather than pathology—of birth that they impart to the birthing woman; 3) the insistence on and support of healthy lifestyles and good nutrition; and 4) the education of clients and informed choice. In regard to uterine rupture, some of the midwife’s preventive techniques are discussed below, with emphasis, of course, on how to avoid the cesarean section in the first place.

What Is Uterine Rupture?

The definition of uterine rupture has become clouded because many people have merged true rupture with dehiscence in their discussions and studies on the topic.(8) This has had the effect of increasing the number of ruptures reported and creating an exaggerated perception of risk. The Landon, et al., study made a clear distinction between the two. It defined uterine rupture as “a disruption or tear of the uterine muscle and visceral peritoneum or a separation of the uterine muscle with extension to the bladder or broad ligament.”(9) This should be called “true” rupture because of the serious clinical signs and consequences that accompany it. These include severe hemorrhage, placental abruption, extrusion of the fetus into the abdomen and death of the mother and/or baby.

Dehiscence, on the other hand, often is not apparent clinically and is only found upon internal palpation of the uterus immediately postpartum or during a cesarean.(10) Delivery room experiences tell us that uterine dehiscence is often not noted or even looked for. If no complication suggests true rupture during pregnancy or birth, then obstetricians usually have no reason to internally palpate a woman’s uterus postpartum. Landon, et al., defined it as “a disruption of the uterine muscle with intact serosa.”(11) The life-threatening situations mentioned above do not happen with a dehiscence and the risks to the mother and baby are vastly different. Therefore, in this paper, dehiscence is used specifically when referring to dehiscence whereas “uterine rupture,” “true uterine rupture” or “rupture” refers to the situation in which the muscle and serosa are both ruptured, leading to clinical signs and surgical treatment.

Prevention of Uterine Rupture

Prevention of complications is a valid component of care for all childbearing women, especially those at risk of uterine rupture. Since midwives tend to approach a woman’s pregnancy as an event that is healthy, normal and part of her natural lifecycle, they focus on the health of the woman first while keeping close eye on any signs of abnormality or disease. The midwife’s prevention of rupture has many components, which are based on good clinical observation and technique, commitment to client education and using techniques that promote successful vaginal birth. Recent studies that compare births of low-risk women birthing at home with midwives with low-risk women birthing at the hospital, midwives have very low intervention rates and comparable mortality rates.(12) Free-standing, midwife-run birth centers had a very low overall rate of 0.4% rupture in women undergoing trial of labor after cesarean, but the rate decreased to 0.2% in women with only one previous cesarean and a gestational age of less than 42 weeks.(13) This is another sign that the fewer cesareans, the better!

Beginning in the prenatal period and continuing through postpartum, many midwives focus heavily on a woman’s nutrition—which may include herbs, supplements or dietary modifications. How is this helpful in preventing uterine rupture?

On a very practical level, healthy mothers generally have healthy pregnancies and healthy babies. Midwives often attest to the impact good or bad nutrition has on pregnancy outcomes and may emphasize nutritional expectations of mothers who choose care with them.(14) This is partly because having the best nutrition for the pregnancy is desirable and partly because out-of-hospital midwives want to decrease the likelihood of any adverse conditions that may arise during birth or postpartum.

For example, green leafy vegetables are recommended for their high mineral and vitamin content, including vitamin K. Vitamin K is, of course, an important component of blood-clotting capability and helps reduce blood loss at birth. Alfalfa has even higher levels of vitamin K and can be taken as capsules or tea.

Red raspberry leaf tea has been the “woman’s” health herb for millennia and helps strengthen the uterine muscle.(15) These plants can positively affect a scarred uterus and reduce the likelihood of rupture.

Nutrition also affects another risk factor for rupture—fetal macrosomia and/or maternal gestational diabetes mellitus (GDM)—because of the higher probability of cesarean that accompanies it. A woman with GDM is more likely to have a cesarean because of concerns over the baby’s size.(16) By consuming more fresh vegetables and fruits, decreasing her intake of processed carbohydrates and exercising more, a woman will be more likely to have better blood sugars and a non-macrosomic baby.(17) Midwives tend to address these concerns often, usually at every prenatal appointment, and even have the chance to effect positive change between a woman’s pregnancies or preconceptually. Once again, preventing the scar helps to prevent the rupture.

The midwifery client’s involvement in education and decisions about her pregnancy and birth is also paramount to preventing complications with uterine rupture because knowledge and empowerment reduce fear. Remember, a mother at risk of rupture is one that has had a cesarean previously. If this woman is to feel confident and secure in choosing VBAC, she needs to be involved in decisions every step of the way—from choosing her daily menu to explaining her choice of homebirth. Virtually every homebirthing woman must deal with family fears or desires about VBAC, potential hospital transport and the politics surrounding midwifery in her area. We all know how being buffeted on all sides with negativity and fear can be tiring or disheartening for a woman. She will need the fortitude that comes with knowledge.

How does education and involvement on the mother’s part affect her chances of uterine rupture? As mentioned above, nutritional choices can strengthen her uterus and provide better blood clotting abilities as well as grow an average-sized baby. Exercise helps her maintain an appropriate weight throughout pregnancy and be in better physical condition at the time of birth. At the time of birth or in the days leading up to it, babies can be in positions that may cause longer or harder labors. By recognizing discomfort and pain in her own body and by doing particular exercises or other treatments that help reposition the baby, the mother reduces her likelihood of cesarean or uterine rupture. In all of these cases, the mother is active in making her choices and affecting her outcome.

Another component of midwifery care is the attention to the physiologic process of birth and its importance to good outcomes. Physiologically, the motherbaby unit has developed a system over the past millennia that has worked extraordinarily well in protecting and nurturing the baby during pregnancy, positioning the baby for the easiest delivery, protecting against hemorrhage, and feeding and warming the newborn. The midwife’s training allows her to follow this system, sustaining it with food, herbs and emotional support, and intervening only when necessary. This allows endogenous oxytocin, the “bonding” and “contracting” hormone, to do its job of maintaining adequate contractions, controlling hemorrhage, helping mom bond with and nurture her baby and starting breastfeeding.

Interventions such as epidurals, opiate analgesics and Pitocin induction or augmentation all lower oxytocin levels or prevent the normal (and extremely high) peak of oxytocin at birth.(18)

What does interference do to this intricate physiologic process? Labor induction and augmentation by means of synthetic chemicals has been implicated in the majority of uterine ruptures in many studies (19), especially in the case of previous uterine surgery, because the chemicals over-stimulate the uterus. Lydon-Rochelle, et al., found that the incidence of rupture when labor was induced with prostaglandins was 24.5/1000, and without prostaglandins it was 7.7/1000.(20) However, with spontaneous onset of labor the incidence of rupture was 5.2/1000, and with repeat cesarean was 1.6/1000. In other words, when a woman with a scarred uterus attempts to have her next baby vaginally, 2.45% of the time she’ll have a rupture if she was induced with prostaglandins, 0.07% of the time she’ll have a rupture if she was induced with Pitocin. But, if she just waits for labor to begin, she’ll rupture 0.05% of the time. If she opts for the planned cesarean, she’ll only rupture 0.0016% of the time—however, she also has an increased risk of morbidity and mortality from the cesarean. Plaut found that the uterine rupture rate for patients attempting VBAC was significantly higher in those who received misoprostol—5.6%—than in those who did not, 0.2%.(21)

These chemicals, along with pain medications, override the body’s intricate hormonal balance, which is normally able to control the strength and rhythm of contractions. They also reduce the chances for a baby with an occipital posterior, military or asynclitic head position to rotate into the easiest and least complicated position. When abnormally strong contractions are paired with a head that is presenting wide diameters, complications can be expected for the uterus and the baby. Therefore, even if the scar has a tensile strength similar to the uterine muscle around it—which means that normal uterine stimulation is not any more risky for the scar than for the unscarred muscle—at some point too much stimulation may be more than the uterus can handle.(22)

At this point, wouldn’t limiting the use of synthetic oxytocics and analgesia—and cesareans, of course—seem reasonable, so that mothers and babies are exposed to fewer risks during the current labor and birth as well as in future pregnancies and births? Wouldn’t helping mothers attain a state of health that would reduce the need for early delivery of their infants also be reasonable? At the very least, mothers and their families need the benefit of full and accurate informed consent, detailing, for example, the increased risk of placenta accreta in future pregnancies after cesarean, with its associated hemorrhages, hysterectomies and blood transfusions.(23) They also should know about the increased risk of uterine rupture with its associated fetal and maternal mortality, hysterectomy, blood transfusion, operative injury and puerperal fever.(24)

Conclusion

We cannot emphasize too strongly that the prevention of the primary cesarean is of utmost importance to reducing the incidence of uterine rupture in this country and to the VBAC debate. Preventing the scar, as well as prohibiting synthetic induction and augmentation agents, prevents almost all the risk. The remaining risk factors can be mitigated in the prenatal or intrapartum period by nutritional changes, by assessing fetal lie correctly and taking appropriate action, or by helping the baby rotate to the desired position through maternal exercises or position changes. Midwives, with their low cesarean rates, have much to teach and to offer the rest of the childbirth community in regard to preventing the primary cesarean and uterine rupture. Furthermore, with their low rates of complications, interventions and negative outcomes, especially with uterine rupture, midwives have nothing to hide and should rejoice in being able to show off their statistics to the rest of the world.

Kristin Eggleston is a student midwife from Washington where she is pursuing a master’s degree in midwifery. She lives there with her homebirthed 4½-year-old son.

References:

www.ican-online.org/resources/statistics.php. Accessed 23 Apr 2007.

Johnson, K.C., and B. Daviss. 2005. Outcomes of planned home births with certified professional midwives: large prospective study in North America. BMJ 330: 1416–19.

Johnson and Daviss; Macfarlane, A., R. McCandlish and R. Campbell. 2000. Choosing between home and hospital delivery: there is no evidence that hospital is the safest place to give birth. BMJ 320: 798.

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